The present invention relates to a method of manufacturing a semiconductor apparatus, a semiconductor production equipment and a cleaning method thereof, more specifically relates to a method of forming a CVD thin film on a surface of a semiconductor substrate, a method of etching a semiconductor substrate, and a method of cleaning a CVD unit and a CVD reactive chamber.
When a thin film is formed by a CVD method on a semiconductor substrate, in a conventional method, a reactive gas (for example, a silane SiH4) as a gas flow 5 for film formation is supplied from outside to an upper portion of a substrate 2 placed on a suscepter 8 provided into a reactive chamber 1 of a CVD unit, shown in FIG. 5.
Gas in supplied via a value 5. A flow rate of the gas is controlled by a mass flow controller 7 so that pressure in the reactive chamber 1 is adjusted to be reduced to about 10 Torr while monitoring a pressure gauge 13. Then, the substrate 2 and the suscepter 8 are heated to 650xc2x0 C. by an external lamp 3 through a quartz-made wall of the reactive chamber 1, while flowing the gas of 1 slm, so that a polycrystal silicon film is formed.
At this time, a boundary domain, which is called as a remaining region 4 where a gas does not flow, appears on a surface of the substrate 2, and a gas for film formation is supplied from the gas flow 5 outside the remaining region 4. The gas for film formation is diffused in the remaining region 4 and gets to the surface of the substrate. Then, the gas is decomposed so that a polycrystal silicon film is deposited.
A thickness of the remaining region 4 is influenced by the gas flow 5. When the gas flow is not uniform, nonuniformity occurs in thickness of the remaining region 4. As a result, the supply of a gas to the surface of the substrate 2 becomes non-uniform, a depositing speed is varied, and thus the film thickness is varied. Moreover, the supply of the gas from the gas flow 5 is usually determined by pressure division of the gas in the gas flow 5, however under the above condition, only several percentage of the gas in the gas flow 5 is supplied to the remaining region 4, and thus only several percentage of the gas introduced into the reactive chamber 1 is used for the deposition.
Therefore, most of the gas introduced into the reactive chamber 1 is not decomposed, and passes through a main valve 9, a pressure adjusting conductance valve 12 and a pipe arrangement 11 so as to be discharged out of a chamber by a pump 10. As a result, cost of forming a thin film rises.
As mentioned above, in the conventional method of forming a thin film on the semiconductor substrate by deposition, since availability of a reactive gas for film formation introduced into the CVD reactive chamber is low, there arises a problem that cost of forming a thin film rises.
The present invention has been achieved in order to solve the above problem, and it is an object of the present invention to provide a method of producing a semiconductor apparatus and a semiconductor production equipment, which are capable of efficiently depositing a thin film on a semiconductor substrate in a reactive chamber by efficiently using a reactive gas for film formation introduced into a CVD reactive chamber when the thin film is formed by a CVD method on the semiconductor substrate, and is thus capable of reducing the cost of forming a thin film remarkably.
In addition, it is another object of the present invention to provide a method of producing a semiconductor apparatus which is capable of efficiently etching a semiconductor substrate by efficiently using an etching gas introduced into an etching chamber when a surface of the semiconductor substrate is etched in the etching chamber, and is thus capable of reducing the etching cost remarkably.
In addition, it is another object of the present invention to provide a method of cleaning a semiconductor production equipment which is capable of efficiently etching and removing a deposit by efficiently using an etching gas introduced into a semiconductor substrate processing chamber when the deposit on an inner wall surface of the semiconductor substrate processing chamber is etched and removed, and is thus capable of reducing the cleaning cost remarkably.
According to the present invention, there is provided a method of producing a semiconductor apparatus, when a thin film is formed by a CVD method on a semiconductor substrate in a CVD reactive chamber, the method comprising the steps of: providing a remaining region where a gas for film formation remains to a proximity of a surface of the semiconductor substrate; and forming a CVD thin film on the substrate by decomposing only the gas for film formation existing in the remaining region without supplying an additional gas from the outside of the remaining region to the remaining region. The step of providing the remaining region may include the steps of: introducing the semiconductor substrate into the CVD reactive chamber so as to reduce pressure in the CVD reactive chamber to not more than a predetermined value; and introducing a reactive gas into the CVD reactive chamber so as to capture the reactive gas in the CVD reactive chamber by stopping the introduction of the reactive gas when the pressure in the CVD reactive chamber obtains the predetermined value. The step of providing the remaining region may be executed with a temperature of the semiconductor substrate being set so that the CVD thin film may be not formed, and the step of forming the CVD thin film may be executed with the semiconductor substrate being heated to a temperature at which the CVD thin film is formed and without supplying an additional reactive gas from the outside of the CVD reactive chamber. The step of providing the remaining region may include reducing pressure in the CVD reactive chamber to not more than a predetermined value; introducing the semiconductor substrate into the CVD reactive chamber; introducing a reactive gas into the CVD reactive chamber so as to form a closed space to be the remaining region in the proximity of the surface of the semiconductor substrate when the pressure in the CVD reactive chamber obtains a predetermined value; and reducing an introducing flow rate of the reactive gas and at the same time introducing an inert gas into the CVD reactive chamber so as to keep the pressure in the reactive chamber at the predetermined value. The step of forming the closed space may be executed with a temperature of the semiconductor substrate being set so that the CVD thin film is not formed, and the step of forming the CVD thin film may be executed with the semiconductor substrate being heated to a temperature at which the CVD thin film is formed and without supplying an additional reactive gas from the outside of the closed space. When the semiconductor substrate is heated, a rear side of the semiconductor substrate may be heated. When the semiconductor substrate is heated, the semiconductor substrate may be moved from an area where the temperature is lower to an area where the temperature is higher.
According to the present invention, there is also provided a semiconductor production equipment, comprising: a CVD reactive chamber for inducing CVD reaction; a suscepter, for placing a semiconductor substrate, which is provided to the outside of the CVD reactive chamber; a first pipe arrangement, for introducing a reactive gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a first mass flow controller and a first valve provided in a midway of the first pipe arrangement; a second pipe arrangement, for introducing an inert gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a second mass flow controller and a second valve provided to a midway of the second pipe arrangement; a third pipe arrangement, for discharging a gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a pressure gauge and a vacuum exhaust pump which are connected to the third pipe arrangement; a main valve provided between a pressure gauge connecting section and a pump connecting section of the third pipe arrangement; heater means for heating the suscepter and a semiconductor substrate via a wall of the CVD reactive chamber; and a valve controller for when a thin film is formed by a CVD method on the semiconductor substrate, controlling the main valve so that the main valve is closed with pressure in the CVD reactive chamber being reduced to not more than a predetermined value and thereafter when the reactive gas is introduced into the CVD reactive chamber, controlling the first valve so that the first valve is closed with the pressure in the CVD reactive chamber being set to a predetermined value.
According to the present invention, there is yet further provided a semiconductor production equipment, comprising: a CVD reactive chamber for inducing CVD reaction; a suscepter, for placing a semiconductor substrate, which is provided into the CVD reactive chamber; remaining region forming means, for forming a remaining region which is separated from an outside, for leaving a constant volume of a gas for film formation, to a proximity of a surface of the semiconductor substrate; heating means for heating the semiconductor substrate; transporting means for transporting the semiconductor substrate from a substrate stand-by chamber to the CVD reactive chamber; gas supplying means for supplying a gas to the remaining region; and gas exhausting means for exhausting the gas from the remaining region. The gas supplying means may be linked with a substrate stand-by chamber, which is freely divided from the CVD reactive chamber. The heating means may be positioned in the outside of the CVD reactive chamber and may heat the semiconductor substrate placed in the CVD reactive chamber. The heating means may heat a rear side of the semiconductor substrate.
According to the present invention, there is still further provided a semiconductor production equipment, comprising: a CVD reactive chamber for inducing CVD reaction; a suscepter, for placing a semiconductor substrate, which is provided to the outside of the CVD reactive chamber; a first pipe arrangement, for introducing a reactive gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a first mass flow controller and a first valve provided in a midway of the first pipe arrangement; a second pipe arrangement, for introducing an inert gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a second mass flow controller and a second valve provided to a midway of the second pipe arrangement; a third pipe arrangement, for exhausting a gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a pressure gauge and a vacuum exhaust pump which are connected to the third pipe arrangement; a main valve and a conductance valve for adjusting pressure, which are provided between a pressure gauge connecting section and a pump connecting section of the third pipe arrangement; a valve controller for independently controlling the valves; a substrate introducing chamber connected to the CVD reactive chamber via a gate valve; a gate valve controller for controlling opening and closing of the gate valve; a substrate transporter for introducing the semiconductor substrate from the substrate introducing chamber into the CVD reactive chamber; an exhausting device for setting pressure in the substrate introducing chamber to a predetermined value; a cover for surrounding a circumference of the semiconductor substrate in front of the suscepter and forming a constant volume of a closed space to be a remaining region for a gas; a cover driving device which is provided so that the cover is moved in front of the suscepter between a position which surrounds the circumference of the semiconductor substrate and a forward position of the position which surrounds the circumference of the semiconductor substrate; and a heater, for heating the suscepter and the semiconductor substrate, which is provided to a rear side of the suscepter in the CVD reactive chamber. When a thin film is formed by a CVD method on the semiconductor substrate, the gate valve controller may open the gate valve with pressure in the substrate introducing chamber and in the CVD reactive chamber being reduced to not more than predetermined values, and after the semiconductor substrate is introduced from the substrate introducing chamber into the CVD reactive chamber, may close the gate valve, and the cover driving device may be provided so as to move the cover in front of the suscepter between the position which surrounds the circumference of the semiconductor substrate and the forward position of the position which surrounds the circumference of the semiconductor substrate, and when a thin film is formed by a CVD method on the semiconductor substrate, may close the cover with the reactive gas being introduced into the CVD reactive chamber and the pressure in the CVD reactive chamber being set to a predetermined value. After the semiconductor substrate is introduced from the substrate introducing chamber into the CVD reactive chamber, the valve controller may control the valves so that the reactive gas is introduced into the CVD reactive chamber with the gate valve being closed so that the pressure in the CVD reactive chamber is set to a predetermined value, and after the cover is closed, the inert gas may be introduced into the CVD reactive chamber so that the pressure in the CVD reactive chamber is set to a predetermined value.
According to the present invention, there is also provided a method of producing a semiconductor apparatus when forming a thin film by a CVD method on a semiconductor substrate in a CVD reactive chamber by using a semiconductor production equipment comprising: a CVD reactive chamber for inducing CVD reaction; a suscepter, for placing a semiconductor substrate, which is provided to the outside of the CVD reactive chamber; a first pipe arrangement, for introducing a reactive gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a first mass flow controller and a first valve provided in a midway of the first pipe arrangement; a second pipe arrangement, for introducing an inert gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a second mass flow controller and a second valve provided to a midway of the second pipe arrangement; a third pipe arrangement, for exhausting a gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a pressure gauge and a vacuum exhaust pump which are connected to the third pipe arrangement; a main valve and a conductance valve for adjusting pressure, which are provided between a pressure gauge connecting section and a pump connecting section of the third pipe arrangement; a valve controller for independently controlling the valves; a substrate introducing chamber connected to the CVD reactive chamber via a gate valve; a gate valve controller for controlling opening and closing of the gate valve; a substrate transporter for introducing the semiconductor substrate from the substrate introducing chamber into the CVD reactive chamber; an exhausting device for setting pressure in the substrate introducing chamber to a predetermined value; a cover for surrounding a circumference of the semiconductor substrate in front of the suscepter and forming a constant volume of a closed space to be a remaining region for a gas; a cover driving device which is provided so that the cover is moved in front of the suscepter between a position which surrounds the circumference of the semiconductor substrate and a forward position of the position which surrounds the circumference of the semiconductor substrate; and a heater, for heating the suscepter and the semiconductor substrate, which is provided to a rear side of the suscepter in the CVD reactive chamber, the method comprising the steps of: reducing pressure in the CVD reactive chamber to not more than a predetermined value; introducing the semiconductor substrate into the CVD reactive chamber; introducing a reactive gas into the CVD reactive chamber so as to form a closed space to be a remaining region in a proximity of a surface of the semiconductor substrate when the pressure in the CVD reactive chamber obtains the predetermined value; reducing an introducing flow rate of the reactive gas and at the same time introducing an inert gas into the CVD reactive chamber so as to keep the pressure in the reactive chamber at the predetermined value; and forming a CVD thin film on the substrate by decomposing only a gas for film formation existing in the remaining region without supplying an additional gas from the outside of the remaining region to the remaining region. When a thin film is formed by a CVD method on the semiconductor substrate, the gate valve controller may open the gate valve with pressure in the substrate introducing chamber and in the CVD reactive chamber being reduced to not more than predetermined values, and after the semiconductor substrate is introduced from the substrate introducing chamber into the CVD reactive chamber, may close the gate valve, and the cover driving device may be provided so as to move the cover in front of the suscepter between the position which surrounds the circumference of the semiconductor substrate and the forward position of the position which surrounds the circumference of the semiconductor substrate, and when a thin film is formed by a CVD method on the semiconductor substrate, may close the cover with the reactive gas being introduced into the CVD reactive chamber and the pressure in the CVD reactive chamber being set to a predetermined value. After the semiconductor substrate is introduced from the substrate introducing chamber into the CVD reactive chamber, the valve controller may control the valves so that the reactive gas is introduced into the CVD reactive chamber with the gate valve being closed so that the pressure in the CVD reactive chamber is set to a predetermined value, and after the cover is closed, the inert gas may be introduced into the CVD reactive chamber so that the pressure in the CVD reactive chamber is set to a predetermined value. The step of forming the closed space may be executed with a temperature of the semiconductor substrate being set so that a CVD thin film is not formed, and the step of forming the CVD thin film may be executed with the semiconductor substrate being heated to a temperature at which the CVD thin film is formed and without supplying an additional reactive gas from an outside of the closed space.
According to the present invention, there is further provided a semiconductor production equipment, comprising: a CVD reactive chamber for inducing CVD reaction; a substrate stand-by chamber which is linked with the CVD reactive chamber; a shutter which freely opens and closes a position which divides the CVD reactive chamber and the substrate stand-by chamber; a shaft which goes through a bottom plate of the substrate stand-by chamber and freely moves up and down; a shaft driving device for driving the shaft in an up-down direction; a cylindrical cover which is provided to a top of a chamber of the shaft, has an opening in a front towards the CVD reactive chamber, surrounds a circumference of the semiconductor substrate with the opening being closed by the semiconductor substrate, and forms a constant volume of a closed space to be a gas remaining region; a first pipe arrangement, for introducing a reactive gas, which is provided to the outside of the substrate stand-by chamber and is connected to the CVD reactive chamber; a first mass flow controller and a first valve which are provided in a midway of the first pipe arrangement; a second pipe arrangement, for introducing an inert gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a second mass flow controller and a second valve which are provided to a midway of the second pipe arrangement; a third pipe arrangement, for exhausting a gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a pressure gauge and a vacuum exhaust pump which are connected to the third pipe arrangement; a first main valve and a first conductance valve for adjusting pressure which are provided between a pressure gauge connecting section and a pump connecting section of the third pipe arrangement; a fourth pipe arrangement, for discharging a gas, which is provided to the outside of the substrate stand-by chamber and is connected to the substrate stand-by chamber; a pressure gauge and a vacuum exhaust pump which are connected to the fourth pipe arrangement; a second main valve and a second conductance valve for adjusting pressure which are provided between a pressure gauge connecting section and a pump connecting section of the fourth pipe arrangement; a valve controller for independently controlling the valves; a substrate introducing chamber which is connected to the substrate stand-by chamber via a gate valve; an exhausting device for reducing pressure in the substrate introducing chamber to a predetermined value; a gate valve controller for opening and closing the gate valve; a substrate transporting unit which has a function for introducing the semiconductor substrate from the substrate introducing chamber into the substrate stand-by chamber, a function for retaining the semiconductor substrate in the substrate stand-by chamber in a position separated from the cover, and a function for placing a surface to be processed of the semiconductor substrate towards the shaft side so as to close the opening of the cylindrical cover; and a heater for heating the semiconductor substrate through a top plate of the CVD reactive chamber.
According to the present invention, there is still further provided a method of producing a semiconductor apparatus, when a thin film is formed by a CVD method on a semiconductor substrate in the CVD reactive chamber by using the semiconductor production equipment, comprising: a CVD reactive chamber for inducing CVD reaction; a substrate stand-by chamber which is linked with the CVD reactive chamber; a shutter which freely opens and closes a position which divides the CVD reactive chamber and the substrate stand-by chamber; a shaft which goes through a bottom plate of the substrate stand-by chamber and freely moves up and down; a shaft driving device for driving the shaft in an up-down direction; a cylindrical cover which is provided to a top of a chamber of the shaft, has an opening in a front towards the CVD reactive chamber, surrounds a circumference of the semiconductor substrate with the opening being closed by the semiconductor substrate, and forms a constant volume of a closed space to be a gas remaining region; a first pipe arrangement, for introducing a reactive gas, which is provided to the outside of the substrate stand-by chamber and is connected to the CVD reactive chamber; a first mass flow controller and a first valve which are provided in a midway of the first pipe arrangement; a second pipe arrangement, for introducing an inert gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a second mass flow controller and a second valve which are provided to a midway of the second pipe arrangement; a third pipe arrangement, for exhausting a gas, which is provided to the outside of the CVD reactive chamber and is connected to the CVD reactive chamber; a pressure gauge and a vacuum exhaust pump which are connected to the third pipe arrangement; a first main valve and a first conductance valve for adjusting pressure which are provided between a pressure gauge connecting section and a pump connecting section of the third pipe arrangement; a fourth pipe arrangement, for discharging a gas, which is provided to the outside of the substrate stand-by chamber and is connected to the substrate stand-by chamber; a pressure gauge and a vacuum exhaust pump which are connected to the fourth pipe arrangement; a second main valve and a second conductance valve for adjusting pressure which are provided between a pressure gauge connecting section and a pump connecting section of the fourth pipe arrangement; a valve controller for independently controlling the valves; a substrate introducing chamber which is connected to the substrate stand-by chamber via a gate valve; an exhausting device for reducing pressure in the substrate introducing chamber to a predetermined value; a gate valve controller for opening and closing the gate valve; a substrate transporting unit which has a function for introducing the semiconductor substrate from the substrate introducing chamber into the substrate stand-by chamber, a function for retaining the semiconductor substrate in the substrate stand-by chamber in a position separated from the cover, and a function for placing a surface to be processed of the semiconductor substrate towards the shaft side so as to close the opening of the cylindrical cover; and a heater for heating the semiconductor substrate through a top plate of the CVD reactive chamber, the method comprising the steps of: reducing pressure in the substrate introducing chamber to not more than a predetermined value with the shutter; reducing pressure in the substrate stand-by chamber to not more than a predetermined value with the shutter being closed and the cover being located in the substrate stand-by chamber; opening the gate valve so as to introduce the semiconductor substrate from the substrate introducing chamber into the substrate stand-by chamber and to retain the semiconductor substrate in the substrate stand-by chamber in a position separated from the cover, and closing the gate valve; after introducing a reactive gas into aid substrate stand-by chamber with the shutter being closed, and placing the surface to be processed of the semiconductor substrate towards the shaft side so that the opening of the cover is closed when the pressure in the substrate stand-by chamber obtains the predetermined value, and forming a closed space to be the remaining region in a proximity of the surface of the semiconductor substrate, reducing an introducing flow rate of the reactive gas; introducing an inert gas into the CVD reactive chamber so as to keep the pressure in the CVD reactive chamber at the predetermined value; heating a top plate of the CVD reactive chamber so as to set a temperature of the CVD reactive chamber to a predetermined value; opening the shutter so as to introduce the cover and the semiconductor substrate into the CVD reactive chamber by moving them by the shaft, and heating a rear side of the semiconductor substrate by heat radiation from the top plate so as to set a temperature of the semiconductor substrate to a predetermined value; and stopping the heating after a constant time passes so as to introduce the cover and the semiconductor substrate into the substrate stand-by chamber by moving them by the shaft, and closing the shutter.
According to the present invention, there is yet further provided a method of producing a semiconductor apparatus, wherein when a surface of a semiconductor substrate is etched in an etching chamber, a remaining region where an etching gas remains in a proximity of the surface of the substrate, is provided, and the surface of the semiconductor substrate is etched only by the etching gas existing in the remaining region without supplying an additional etching gas from the outside of the remaining region to the remaining region.
According to the present invention, there is also provided a method of cleaning a semiconductor production equipment, wherein when a deposit which is deposited on an inner wall surface of a semiconductor substrate processing chamber is removed by etching, after an etching gas for removing a deposit is introduced into the processing chamber, the etching gas remains in the processing chamber, and the deposit is removed by etching without supplying an additional etching gas from the outside.
Additional object and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The object and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.